Case Study

New England Business Service (NEBS) - Peterborough, NH

New England Business Service's Peterborough, New Hampshire facility is a paper forms
printing plant.

The building's major mechanical systems include:

19 - 20 ton York Package Cooling Units with Economizers

1 - 40 ton Cooling Unit with Steam Reheat

9 - Steam Heating and Ventilating Units

9 - 15 tons or less Cooling Units with Steam Heat Coils

2 - Low Pressure Cleaver Brooks Steam Boilers

Phase One of this project involved replacing the existing DDC system with a Delta
Controls ORCA Series DDC system. The existing system was no longer manufactured and
had Y2K issues. While updating the equipment, corporate and local facility
management put forth a list of goals that they wanted to accomplish during the
replacement. These included:

Minimize operating and energy expenses.

Track the buildings mechanical performance.

Control the 19 new York cooling units.

Control the ventilation requirements using motorized dampers and Carbon Dioxide sensors.

Control the buildings internal static pressure.

Install a Graphical Operator Interface.

Reduce the operator workload in the day-to-day operations of the HVAC system.

R. L. Shields Associates, Inc. installed 4 Delta Controls ORCA Series DCU Controllers
to replace the existing 1980 vintage system. The DCU's were interconnected by a 1 Mb
high speed network. The 19 new York cooling units are being controlled by Delta
Controls Zone Controllers. They are networked together and connected to the
Maintenance Department DCU.

To control ventilation requirements, Carbon Dioxide (CO2) sensors were installed in the
office and production areas. As CO2 levels rise, the outside dampers modulate open
to keep the CO2 readings below maximum acceptable levels. Carbon Dioxide has become
an acceptable method of controlling ventilation requirements and is recognized by ASHRAE
as one method of monitoring air quality.

To control building static pressures, a network of sensing ports was installed around
the four sides of the building. This building has a history of running a negative
static pressure. This was a concern because of drafts and blowing paper. Since
the Delta Zone Controllers allowed full control over the dampers in the 19 new York units,
as the static pressure starts to go negative, the dampers begin to modulate open to allow
outside air to enter the building through the cooling units rather than the doors.

Some special software was developed by R. L. Shields Associates for use on this site
and others.

Demand Side Management Software - This software is used to calculate the electrical
demand, consumption and projects demand based on a minute by minute calculation. This
enables the computer and operator to make changes in operation to avoid setting demand
peaks. To better understand Electric Demand, click here.

Sunrise/Sunset Time Calculation - This controls the parking lot and building exterior
lighting based on Sunrise and Sunset. The eliminates the problems associated with power
failures skewing the time clocks and provides for the adjustment to Daylight Savings Time
and Daylight Standard Time.